DAC in cyber stands for Discretionary Access Control, a decentralized approach to managing who can access specific digital resources.
Understanding Discretionary Access Control (DAC)
Discretionary Access Control (DAC) is a security model where resource owners have the authority to decide who gets access to their data. This contrasts with other access control models where access is centrally managed by an administrator or based on predefined rules. In a DAC system, users are granted access permissions based on the owner's discretion. The reference material specifies that DAC represents a decentralized approach to managing access permissions.
Key Characteristics of DAC
- Decentralized Management: Owners, not a central administrator, control access.
- Least Privilege: Users should receive only the access they need to perform their tasks.
- Owner Control: Resource owners decide who can access their data.
How DAC Works
- Resource Creation: A user creates a resource (e.g., a file, a database record).
- Ownership: The creator automatically becomes the owner of the resource.
- Permission Granting: The owner assigns permissions to other users or groups, specifying what actions they can perform (e.g., read, write, execute).
Example of DAC in Action
Imagine Alice creates a document on a shared server. With DAC, Alice, as the owner, can decide that:
- Bob can read the document.
- Carol can read and write to the document.
- David has no access to the document.
Advantages of DAC
- Flexibility: Owners have fine-grained control over their resources.
- Ease of Implementation: Relatively simple to set up compared to more complex models.
- User Empowerment: Puts access control in the hands of those who understand their data best.
Disadvantages of DAC
- Security Risks: Vulnerable to privilege escalation and Trojan horse attacks if users are not careful.
- Administrative Overhead: Can become complex to manage in large organizations with numerous resource owners.
- Lack of Centralized Control: Difficult to enforce consistent security policies across the entire system.
Alternatives to DAC
Other access control models include:
- Mandatory Access Control (MAC): Access is determined by a central authority based on security labels.
- Role-Based Access Control (RBAC): Access is based on the roles that users have within an organization.
Summary Table: DAC at a Glance
| Feature | Description |
|---|---|
| Definition | Decentralized access control managed by resource owners. |
| Management | Resource owners decide who can access their data. |
| Access Granting | Owners assign permissions to other users or groups. |
| Advantages | Flexibility, ease of implementation, user empowerment. |
| Disadvantages | Security risks, administrative overhead, lack of centralized control. |
| Key characteristic | Users receive the least access necessary for their tasks. |
